This T32 Training Grant has focused successfully over the past 30 years on providing a dynamic research training environment for pathologists, other physician-scientists and basic scientists working in the molecular pathology of cancer. Over the past two 5-year funding periods, trainees have published a considerable number of papers, including in high quality journals, and have found faculty positions in prestigious medical schools. The present proposal features 20 Harvard Medical School and Massachusetts Institute of Technology faculty who are centered in the Massachusetts General Hospital Molecular Pathology Unit and Center for Cancer Research. This interactive, overlapping community of scientists and physician-scientists is organized into thematic programs in cancer genetics; animal models of cancer; mechanisms of gene expression and protein folding; cell cycle control and DNA damage repair; stem cell biology; and in vivo imaging for cancer biology and diagnosis. As in previous cycles, the trainees will be selected from a competitive pool of MD, MD-PhD and PhD applicants on the basis of prior academic and research achievements and evidence of a strong commitment to a career in cancer biology. The period of training will be two or three years for each successful applicant. An active and program-specific recruitment and retention program to enhance diversity ensures that diverse applicants have access to, and succeed in, the training program. In summary, the proposed T32 program renewal capitalizes on a highly interactive, experienced and focused faculty; a distinguished record of training productive physicians and scientists, including underrepresented minorities; state-of-the- art facilities and educational resources; and exposure of the trainees to basic and translational aspects of cancer biology.